There is a major interaction between Cymbalta (duloxetine) and alcohol in individuals with a history of substantial alcohol intake or abuse. There does not appear to be much of a risk with social drinkers (although caution is still advised).
According to the prescribing information for Cymbalta:
"Although Cymbalta does not increase the impairment of mental and motor skills caused by alcohol, use of Cymbalta concomitantly with heavy alcohol intake may be associated with severe liver injury. For this reason, Cymbalta should not be prescribed for patients with substantial alcohol use".
Typically, one of the biggest concerns in regard to taking medication with alcohol is the risk of additive sedation and cognitive impairment. This does not appear to be an issue with Cymbalta and intermittent alcohol consumption.
However, as seen from the passage above, there does appear to be a risk of liver injury in those with a history of substantial alcohol use. The following is more information provided by the prescribing information:
"When Cymbalta and ethanol were administered several hours apart so that peak concentrations of each would coincide, Cymbalta did not increase the impairment of mental and motor skills caused by alcohol. In the Cymbalta clinical trials database, three Cymbalta-treated patients had liver injury as manifested by ALT and total bilirubin elevations, with evidence of obstruction. Substantial intercurrent ethanol use was present in each of these cases, and this may have contributed to the abnormalities seen."
Because of the risk of liver related injuries, Cymbalta should not be taken in those with a history of substantial alcohol use. If you wish to drink socially while taking Cymbalta, it would be prudent to discuss with your doctor as they have your complete medical history. You may also want to have your liver function tested if you are concerned.